Reflection: Checks for Understanding Missing Numbers in Japanese - Section 2: Missing Number Equation Practice


There are still students who add first and think later. They approach every problem with adding. They add the 2 numbers they see without really looking at what the equation says. 

It is important for students to be able to reason in mathematics. Reasoning includes figuring out whether they are being asked to add or subtract. 

As I circulate around the room I stop to ask students to explain their thinking. I ask for them to try to solve an equation that they have already filled in to see if it makes sense. If they have written 19 + ________ = 35 and they have written 54 in the center box, I ask them to recheck the problem by adding 19 and 54 as they have written to see if they get 35. At first they look at me as if I have 3 heads. Of course that is the answer and they tell me how they counted it, or they show me their expanded form. I say, just try it again. They do it out and are surprised that it didn't work. I explain to them that they added the 2 numbers correctly, but the problem didn't ask them to do that. Do they think they could try to figure out what the problem was asking? 

 I suggest a number line which is more visual and can help students see that 54 would not fit in the equation. 

I want to encourage students to "see" math and have it make sense, so they can use math later on in a positive way.

  Adding Everything
  Checks for Understanding: Adding Everything
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Missing Numbers in Japanese

Unit 12: More Complex Numbers and Operations
Lesson 10 of 10

Objective: Students will be able to complete math sentences where the missing number can be found in any position.

Big Idea: Students build a stronger understanding of number and tie it in to Japanese counting and to provides a great review.

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Math, Number Sense and Operations, addition, subtraction, place value strategies
  55 minutes
screen shot 2014 05 13 at 7 51 07 pm
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